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PubMed1986

Susceptibility testing of slowly growing mycobacteria by a microdilution MIC method with 7H9 broth.

Based on previous success with rapidly growing mycobacteria, a microdilution MIC system was devised for slowly growing mycobacterial species using 7H9 broth. Test drugs included isoniazid, rifampin, ethambutol, streptomycin, clofazamine, and sulfamethoxazole. Sixty isolates of four mycobacterial species, including Mycobacterium tuberculosis, from patients who had never received drug therapy were evaluated in the system, as well as 25 drug-resistant isolates and 11 control strains. MICs were read when good macroscopic control growth was evident, a period which varied with each species. Most species exhibited a narrow range of MICs with easily discernible growth endpoints. The aminoglycosides, ethambutol, clofazamine, and sulfamethoxazole were the only drugs with activity against all species at clinically achievable levels in serum. Correlation between susceptibilities by the proportion method in agar with single drug concentrations and the broth method were excellent for M. tuberculosis, M. kansasii, and M. marinum for isoniazid, rifampin, and ethambutol. Isolates of the M. avium complex were much more susceptible in broth than in agar for rifampin, ethambutol, and streptomycin. Given the successful transition of most microbiology laboratories to MIC plates for other bacterial species, this method would allow for testing of multiple drugs at multiple concentrations and has good potential for evaluation of drug combinations and drug-resistant isolates.

Anti-Bacterial Agents↗
PubMed2000

Evaluation of the BBL MGIT (Mycobacterial growth indicator tube) AST SIRE system for antimycobacterial susceptibility testing of Mycobacterium tuberculosis to 4 primary antituberculous drugs.

OBJECTIVE: To evaluate the performance of the BBL MGIT (Mycobacterial Growth Indicator Tube) AST SIRE system for the antimycobacterial susceptibility testing of Mycobacterium tuberculosis to isoniazid (at a concentration equivalent to the lower concentration used for testing by the method of proportion), rifampin, ethambutol, and streptomycin. DESIGN: Thirty-one clinical isolates and 30 challenge strains provided by the Centers for Disease Control and Prevention (CDC) were tested by MGIT AST SIRE using 2 methods of inoculum preparation, and results were compared with those of the method of proportion, which was considered the reference method. Clinical isolates for which the results of the 2 methods were discordant also were tested at 2 reference laboratories. RESULTS: Based on data from our site and the reference laboratories, agreement rates between initial MGIT AST SIRE results and the method of proportion for the clinical isolates with the inoculum prepared from a McFarland equivalent and from a positive MGIT tube, respectively, were 100% and 96.8% for isoniazid, 100% and 100% for rifampin, 96.8% and 100% for ethambutol, and 100% and 100% for streptomycin, excluding the isolate for which the discordant streptomycin result could not be resolved. For the 30 challenge isolates, agreement rates between MGIT AST SIRE and expected results and between method of proportion and expected results, respectively, were 96.7% and 93.3% for isoniazid, 93.3% and 100% for rifampin, 83. 3% and 100% for ethambutol, and 93.3% and 100% for streptomycin. For the clinical isolates, the mean time to an MGIT AST SIRE result of susceptible was 6.15 +/- 0.13 days (range, 5-8 days). For a result of resistant, the mean time overall was 5.00 +/- 0.24 days (range, 3-8 days). CONCLUSION: These data suggest that the MGIT AST SIRE system, using either method of inoculum preparation, is an acceptable alternative to the BACTEC 460 TB method of susceptibility testing of clinical isolates of M tuberculosis to isoniazid, rifampin, ethambutol, and streptomycin. Reasons for the lower agreement with the CDC challenge isolates should be investigated. Further evaluation of the MGIT AST SIRE system using a concentration of isoniazid equivalent to the higher concentration tested by the method of proportion would be useful, because the decision concerning use of this agent generally is based on the susceptibility test result at the higher concentration.

Antitubercular Agents↗
PubMed1975

Investigations of allergic status and blood counts in Chinese patients receiving daily or intermittent rifampicin in Hong Kong.

In a controlled trial in Hong Bong, 575 Chinese patients with pulmonary tuberculosis whose treatment with first-line regimens had failed were allocated at random to the following retreatment regimens of chemotherapy. (1) Rifampicin plus ethambutol daily (ER7). (2) Rifampicin plus ethambutol twice a week (ER2). (3) Rifampicin plus ethambutol once a week (ER1). (4) Rifampicin plus ethambutol daily for 2 months and then once a week (ER7ER1). (5) Ethionamide plus pyrazinamide plus cycloserine daily for 6 months and then ethionamide plus pyrazinamide daily (EtZC), as a control regimen. Answers to a questionnaire on allergic disease, the results of prick tests with standard allergens, ABO blood grouping, size of tuberculin response during chemotherapy, and a rifampicin patch test showed no associations with the occurrence of adverse reactions to daily or intermittent rifampicin. Mantoux testing during chemotherapy provided no evidence of an immunosuppressive effect of rifampicin. Mean platelet counts at 12 months were significantly lower than those at 3 months on the two once-weekly regimens (ER1, ER7ER1) and on the control regimen (EtZC), although still within normal limits. At 3 months, but not at 12 months, mean platelet counts on the two once-weekly regimens were significantly lower 6 hr after a dose of the regimen than they were before the dose.

ABO Blood-Group System↗
PubMed2006

[Vision impairment in the course of lung tuberculosis treatment].

A 51-year-old male patient developed irreversible blindness following pulmonary tuberculosis treatment. The patient's medical history was reviewed, and thorough ophthalmologic examination undertaken (visual acuity, intraocular pressure, Kugel-Perimeter visual field checkup) on initial examination and throughout the next 2 years during the third month treatment with isoniazide, rifampicin, pirazinamide and ethambutol. Ocular symptoms occurred at 3 weeks of the initial symptoms, the patient was examined by an ophthalmologist, and treatment with ethambutol was discontinued; visual impairment progressed to bilateral optic nerve atrophy; almost no signs of improvement were found during the next 2 years of observation, in spite of treatment. Ethambutol is known to be an antituberculotic associated with ocular toxicity. Even in recommended dosage, ethambutol can lead to unpredictable and permanent damage to the optic nerve. The exact mechanism for optic neuritis has not yet been explained.

Antitubercular Agents↗
PubMed1975

Short-course chemotherapy in pulmonary tuberculosis. A controlled trial by the British Thoracic and Tuberculosis Association.

The results of short courses of chemotherapy using rifampicin plus isoniazid, supplemented for the first two months by streptomycin or ethambutol, in patients with newly diagnosed pulmonary tuberculosis, have been studied. 174 patients with little or no cavitation received six months chemotherapy. 1 (0.6%) failed to convert to culture negative during treatment and 5 (3%) relapsed in the twelve months after the end of treatment. In 177 patients with similar disease, twelve months chemotherapy was 100% effective in rendering the sputum culture negative and in preventing relapse in the six months after the end of treatment. 151 patients with more extensive cavitation received chemotherapy for nine months; this was 100% effective in sputum conversion and in preventing relapse in the nine months after the end of treatment. In 155 patients with similar disease, the eighteen-month regimen was uniformly successful in sputum conversion. The rifampicin plus isoniazed regimen was well tolerated, producing adverse effects which warranted withdrawal from the study in only 3.6% of patients. Comparison of ethambutol with streptomycin as a third drug given for the first eight weeks showed no significant difference in the rate of sputum conbersion nor in the incidence of relapse. Streptomycin produced significant adverse effects in 8% of patients whilst ethambutol caused none. Chemotherapy with rifampicin plus isoniazed for nine months, supplemented initially by ethambutol, is more acceptable than standard chemotherapy for eighteen months, is highly effective in sputum conversion, and has resulted in no relapses over a nine-month follow-up period. Further follow-up is being continued to confirm that relapse does not occur.

Administration, Oral↗
PubMedDate not supplied

Neurological manifestations and toxicities of the antituberculosis drugs. A review.

The neurological manifestations and toxicities of 12 antituberculosis drugs [isoniazid, rifampicin (rifampin), ethambutol, p-aminosalicylic acid, pyrazinamide, streptomycin, kanamycin, ethionamide, cycloserine, capreomycin, viomycin and thiacetazone] are reviewed. Their effects upon the central nervous system, cranial nerves, peripheral nerves and the neuromuscular junction are examined, and drug interactions of neurological concern are briefly discussed. Isoniazid is well known to increase the concentrations of gamma-aminobutyric acid in neural tissues. Although conflicting data have been published, isoniazid may play a limited future role in reducing the degree of adventitious movements noted in certain neurological diseases such as multiple sclerosis, spasmodic torticollis, and other segmental dystonic syndromes. With rifampicin neurological complications have been observed infrequently. Rifampicin penetrates into the CSF and has been shown to have useful activity against various micro-organisms in the CSF, including certain viruses; however, contrary to earlier suggestions, it appears to have no role in the treatment of subacute sclerosing panencephalitis. A number of studies have indicated that isoniazid is associated with a large number of accidental and intentional poisonings. The highest incidence has been observed with Southwestern American Indians in which this agent was involved in 7% of all suicide attempts and 19% of the suicide deaths. Degeneration of the optic chiasma and nerve is a well-known adverse effect of ethambutol; toxicity is manifested by impairment of visual acuity, marked loss of colour discrimination, constricted visual fields, and central and peripheral scotoma. Ototoxicity is a well known problem caused by streptomycin, kanamycin, capreomycin and viomycin. The use of streptomycin in pregnant mothers is associated with congenital deafness in newborns in certain cases. The aminoglycoside antibiotics are also associated with flaccid paralysis following neuromuscular blockade. Adverse reactions to cycloserine are mainly dose-related with neurological and psychiatric syndromes noted in up to 50% of patients. Recent data indicate that isoniazid, rifampicin, ethambutol, pyrazinamide, streptomycin, kanamycin, ethionamide, and cycloserine appear in measurable quantities in the cerebrospinal fluid. Five of these compounds (isoniazid, rifampicin, ethambutol, kanamycin, cycloserine) pass to some degree through non-inflamed meninges. Other than discontinuation of the therapeutic regimen and general supportive measures, very few methods are described in the literature for treatment of acute intoxications with antituberculosis drugs.

Antitubercular Agents↗
PubMed1992

Stability of antimycobacterial drugs in susceptibility testing.

Aqueous solutions of 0.02% isoniazid, 0.2% streptomycin, 0.2% para-aminosalicylate, and 0.5% ethambutol and ethylene glycol solutions of 0.5% ethionamide stored at 3 to 7 degrees C remained stable for 1 year, as did aqueous solutions of 0.05% ethionamide hydrochloride, 0.05% kanamycin, 0.05% viomycin, and 0.1% capreomycin stored at -20 degrees C. The ethambutol and capreomycin solutions were tested by microbiologic methods; the other solutions were tested by both spectrophotometric and microbiologic methods. Prepared susceptibility testing media made with cycloserine, rifampin, and the above solutions incorporated into Middlebrook 7H10 medium showed acceptable stability when stored at 3 to 7 degrees C for 1 month. During incubation of the test medium at 37 degrees C, approximately half of the activity of isoniazid, ethionamide, ethambutol, cycloserine, and rifampin was lost after periods ranging from 2 to 4 days for ethambutol to 2 weeks for rifampin.

Antitubercular Agents↗
PubMed1995

Intracellular activities of roxithromycin used alone and in association with other drugs against Mycobacterium avium complex in human macrophages.

Recent reports have shown that roxithromycin possesses significant activity against atypical mycobacteria, including the Mycobacterium avium complex (MAC), and that its extracellular anti-MAC activity is further enhanced in two- or three-drug combinations with ethambutol, rifampin, amikacin, ofloxacin, and clofazimine. In accordance with the above data, the anti-MAC potential of roxithromycin used alone and in combination with the above-mentioned antituberculous drugs was screened intracellularly against five clinical MAC isolates (from both human immunodeficiency virus-positive and human immunodeficiency virus-negative patients), phagocytized by human monocyte-derived macrophages. The results showed that roxithromycin used alone and within clinically achievable levels was active against all of the MAC isolates tested. Screening of two-drug combinations showed that both rifampin and clofazimine further increased the intracellular activity of roxithromycin against all five isolates by 35 to 80% (ethambutol, ofloxacin, and amikacin resulted in increased intracellular activity against one, two, and four isolates, respectively). For the three-drug combinations, the combination of roxithromycin plus ethambutol used with rifampin or clofazimine was the most uniformly active against all five MAC isolates, with activity increases of 42 to 90%, followed by roxithromycin plus ethambutol used with amikacin, which resulted in activity increases of 15 to 90%. The overall level of intracellular killing after 5 days of drug addition, in comparison with growth in untreated controls, varied from 1 to 3 log units depending on the individual MAC isolate and/or drug combination used.

Cells, Cultured↗
PubMed1995

Synergistic activities of clarithromycin and antituberculous drugs against multidrug-resistant Mycobacterium tuberculosis.

The rise of multidrug-resistant Mycobacterium tuberculosis has complicated therapy for tuberculosis and led us to search for a potentially active combination of drugs against these strains. The susceptibilities of 12 strains of multidrug-resistant M. tuberculosis to standard antituberculous drugs (isoniazid, rifampin, ethambutol, and pyrazinamide), clarithromycin, and its metabolite, 14-hydroxyclarithromycin, were determined by use of the BACTEC radiometric method. All strains were resistant to at least two of the antituberculous drugs. Clarithromycin and 14-hydroxyclarithromycin MICs were in the range indicating resistance at > or = 8.0 micrograms/ml for all strains. Combination testing by the BACTEC method was performed with various concentrations of isoniazid, rifampin, and ethambutol, and with clarithromycin/14-hydroxyclarithromycin at fixed concentrations of 2.0/0.5 micrograms/ml, respectively. Addition of clarithromycin/14-hydroxyclarithromycin to these antituberculous drug mixtures resulted in a 4- to 32-fold reduction in MICs of isoniazid, rifampin, and ethambutol and made resistant strains susceptible. Fractional inhibitory concentrations ranged from 0.23 to 0.50 for all strains, suggesting a synergistic interaction between standard antituberculous drugs and clarithromycin/14-hydroxyclarithromycin. The ability of clarithromycin/14-hydroxyclarithromycin to enhance the activities of isoniazid, ethambutol, and rifampin in vitro suggests that this combination may be efficacious in the treatment of multidrug-resistant M. tuberculosis infections.

Antitubercular Agents↗
PubMed1998

Evaluation of a new method for rapid drug susceptibility testing of Mycobacterium avium complex isolates by using the mycobacteria growth indicator tube.

The reliability of the Mycobacteria Growth Indicator Tube (MGIT [BBL]) for rapid drug susceptibility testing of Mycobacterium avium complex (MAC) isolates was evaluated. MICs of amikacin, clarithromycin, clofazimine, ethambutol, and rifabutin were determined by the MGIT system for 16 MAC strains. The results were compared with those obtained by the BACTEC broth macrodilution method. The turnaround times were 6 to 8 days (median, 7 days) for the MGIT and 5 to 7 days (median, 6 days) for the BACTEC system. Agreements with BACTEC system-determined MICs, within +/-1 log2 dilution, were 100, 100, 88, 63, and 44% for amikacin, clofazimine, rifabutin, clarithromycin, and ethambutol, respectively. Within +/-2 log2 dilutions, agreement with BACTEC system-determined MICs increased to 100% for all the tested drugs. In addition, if MGIT-determined MICs were evaluated according to the thresholds adopted for the interpretation of BACTEC system-determined ones, ethambutol was the only drug for which susceptible strains were frequently misclassified as resistant. It is concluded that the MGIT system is a promising, nonradiometric alternative to the BACTEC method for rapid susceptibility testing of MAC isolates; however, additional studies are required to confirm our results and to determine the optimal criteria for the interpretation of ethambutol MICs.

Microbial Sensitivity Tests↗
PubMed2004

Multicenter evaluation of the MB/BACT system for susceptibility testing of Mycobacterium tuberculosis.

The reliability of the MB/BACT system for susceptibility testing of Mycobacterium tuberculosis to pyrazinamide, rifampin, isoniazid, streptomycin, and ethambutol was compared to the BACTEC 460TB system. The proportion method was used to resolve discrepant results by an independent arbiter. Two interpretative methods were used, with an undiluted control (direct control) and a diluted control (10(-1) control). As no significant difference was observed between the two controls, the method with the direct control was adopted as the most accurate one. One hundred sixty-six strains were tested, with an overall agreement of 98.3%. After resolution of the 18 discrepant results by the proportion method, the sensitivity and specificity of the MB/BACT system were 100% for rifampin, isoniazid, and pyrazinamide. For ethambutol, sensitivity was 92.3% at the critical concentration and 33% at the high concentration, and specificity was 100% at both concentrations. For streptomycin, sensitivity was 100% at the critical concentration and 80% at the high concentration, and specificity was 98.6% at the critical concentration and 100% at the high concentration. The rifampin, isoniazid, streptomycin, and ethambutol susceptibility test results were obtained in 6.6 days with the MB/BACT versus 5 days with the BACTEC 460TB. The pyrazinamide susceptibility test results were obtained in 7.8 days with the MB/BACT, versus 6.7 days with the BACTEC 460TB. These data demonstrate that the fully automated MB/BACT system is a very reliable method for rapid susceptibility testing of M. tuberculosis against rifampin, isoniazid, and pyrazinamide. Sensitivity results have to be improved for ethambutol and streptomycin, especially at the high concentration.

Antitubercular Agents↗
PubMed1987

Five-year follow-up of a controlled trial of five 6-month regimens of chemotherapy for pulmonary tuberculosis. Hong Kong Chest Service/British Medical Research Council.

In a study in Hong Kong, Chinese patients with sputum-smear-positive pulmonary tuberculosis were allocated at random to five 6-month antituberculosis regimens. Four were pyrazinamide-containing regimens: 3 of these were given 3 times a week throughout, and contained isoniazid, rifampin, and pyrazinamide together with (1) streptomycin and ethambutol (HRZSE3), (2) streptomycin but no ethambutol (HRZS3), and (3) ethambutol but no streptomycin (HRZE3). The fourth contained the same drugs as Regimen 3, but was given daily throughout (HRZE7). The fifth regimen contained isoniazid, rifampin, streptomycin, and ethambutol, given 3 times a week, but no pyrazinamide (HRSE3). As previously reported, all 833 patients with drug-susceptible strains of tubercle bacilli pretreatment had a favorable bacteriologic response during chemotherapy, and bacteriologic relapse during the 2 yr (18 months after the end of chemotherapy) occurred in 9 (1.4%) of 626 patients in the pyrazinamide series (Regimens 1 to 4 combined) compared with 13 (7.8%) of 166 in the nonpyrazinamide series (Regimen 5) (p less than 0.001). The patients have been assessed at 4 and 5 yr after admission to the study. During the 5 yr, the total relapse rates for patients with drug-susceptible strains pretreatment were 3.4% for the pyrazinamide series compared with 10.3% for the nonpyrazinamide series (p less than 0.001). The results for the pyrazinamide series were also very good for the 104 assessable patients with strains resistant to isoniazid, streptomycin, or both drugs pretreatment: there was 1 failure during chemotherapy, 1 relapse during the first 2 yr and 2 subsequent relapses.

Adolescent↗
PubMed1998

G-CSF association with prolonged survival in HIV-infected patients with disseminated Mycobacterium avium complex infection.

Clarithromycin can ameliorate symptoms and improve survival in disseminated Mycobacterium avium complex (DMAC) infection. Optimal combinations of this drug with other agents remain unknown. Granulocyte colony stimulating factor (G-CSF) is a cytokine that can improve phagocytosis of M. avium complex in vitro. We aim to determine if G-CSF administration is associated with improved survival in patients with DMAC in a retrospective, cohort study. Case records from 1991 to 1995 of 91 patients with DMAC at Parkland Memorial Hospital were reviewed for date of initial DMAC diagnosis, baseline CD4 count, race, sex, antiretroviral use, G-CSF use, therapy for DMAC (clarithromycin, ethambutol, ciprofloxacin and rifabutin) and date of death. Of 91 cases identified, 25 were treated with G-CSF and 66 never received this drug. Baseline characteristics were similar in each group including CD4 count (40 cells/mm3 vs 33 cells/mm3, P=0.68), clarithromycin use (18 patients vs 52 patients, P=0.90), and antiretroviral use (20 patients vs 42 patients, P=0.21). Subjects treated with G-CSF lived longer than those who did not receive this drug (355 days vs 211 days, P<0.01). In the subgroup treated with clarithromycin, G-CSF was also associated with increased survival (377 days vs 252 days, P<0.01). Cox proportional hazards model showed a decreased risk of death in patients treated with G-CSF (RH=0.22, P<0.01), clarithromycin (RH=0.13, P<0.01) and ethambutol (RH=0.51, P=0.02). Ciprofloxacin and rifabutin use did not influence survival. These data support the use of clarithromycin and ethambutol in the treatment of DMAC. Addition of G-CSF to a regimen of clarithromycin and ethambutol may increase survival in DMAC and should be studied prospectively.

AIDS-Related Opportunistic Infections↗
PubMedDate not supplied

Drug resistance to the first line of antitubercular regimen (a preliminary report).

Sputum samples from 100 patients of pulmonary tuberculosis were processed. These patients were admitted in group of Tuberculosis Hospital at Sewri, Mumbai, which is a referral tuberculosis hospital. Isolates were identified as M. Tuberculosis by biochemical tests. Antitubercular sensitivity testing for Isoniazid, Rifampicin, Ethambutol and Streptomycin was performed by resistance ratio method. Total resistance was 36% in our study. Resistance to Isoniazid was 61%: to Rifampicin was 50%, to Ethambutol was 8% and to Streptomycin was 41%. Primary drug resistance to Isoniazid was 45% to Rifampicin was 27%, to Ethambutol was 9%, and to Streptomycin was 54%. Secondary drug resistance to Isoniazid was 68% to Rifampicin was 60%, to Ethambutol was 8% and to Streptomycin was 36%. Secondary drug resistance to Isoniazid and Rifampicin is rising as compared to primary drug resistance to Isoniazid and Rifampicin. This is statistically significant (p < 0.001). 11 out of 36 cases (30%) showed multi drug resistance to Isoniazid and Rifampicin.

Antitubercular Agents↗
PubMed2002

Drug-resistant tuberculosis in Ethiopia: problem scenarios and recommendation.

Tuberculosis (TB) is a major public health problem in Ethiopia. This review is prepared to indicate possible future challenges related to tuberculosis control and it includes previous reports of drug-resistant surveys in Ethiopia. Drug-resistant TB, both initial and acquired, was reported from different regions of the country. In studies from 1984 to 2001, the initial resistance to isoniazid ranges from 2% to 21% and initial resistance to streptomycin ranges from 2 to 20%. Multidrug-resistance (MDR) TB defined as resistance to at least isoniazid and rifampicin was also reported in about 1.2% of new cases and 12% of re-treatment cases. In all studies which included ethambutol susceptibility test, ethambutol resistance is either nil or very low (below 0.5%). All MDR isolates were susceptible to ethambutol. Treatment and re-treatment regimens recommended by the National TB/Leprosy Control Program could be effective on all cases other than those with MDR-TB. MDR-TB is difficult to cure. Therefore, special emphasis should be given to control the spread of MDR-TB. Lack of control efforts may lead to the increased resistance to both first- and second-line drugs. A well supported and controlled special treatment unit, which uses both first-line and second-line drugs is required for a proper management of these cases and for effective control of the spread of MDR-TB. A uniform susceptibility to ethambutol can be taken as an advantage to develop standard low-cost re-treatment regimen for MDR-TB patients.

Antitubercular Agents↗
PubMed1993

[Incidence of tuberculostatic-resistant Mycobacterium tuberculosis. Clinical aspects and impact on therapy and clinical course].

BACKGROUND: To know the incidence of Mycobacterium tuberculosis resistant to anti-tuberculin drugs in addition to the clinical features, treatment and evolution of the patients. METHODS: This was a retrospective study of the clinical histories of patients with isolation of Mycobacterium tuberculosis with some type of resistance studied from January 1980 to April 1992. RESULTS: During the period studied 470 patients were diagnosed with tuberculosis by cultures. In 30 of these cases (6.4%) Mycobacterium tuberculosis resistant to Isoniazide (8), Streptomycin (6), Isoniazide + Rifampicin (4), Isoniazide + Streptomycin (3), Isoniazide + Ethambutol (2), Isoniazide + Rifampicin + Streptomycin (2), Isoniazide + Rifampicin + Ethambutol (2), Rifampicin (1), Ethambutol (1), Isoniazide + Pyrazinamide (1) and Isoniazide + Rifampicin + Streptomycin + Ethambutol (1) were isolated. Clinical information was obtained on 23 patients, with the most frequent clinical pictures being those of respiratory infection (15). Five cases occurred in HIV+ patients. The resistance was considered as primary in 58.97% of the cases with modifications in empiric treatment being necessary in 6 cases. In 15 out of the 19 patients from whom the data of the follow up was obtained the evolution was good. CONCLUSIONS: Resistance to Mycobacterium tuberculosis was 6.4%, with the high number of strains resistant to Rifampicin being of note. In 79% of the cases in which follow up data was obtained the resistance had no impact on treatment due to the good evolution of the patients in relation with the treatment used.

Adult↗
PubMed1988

Neurotoxicity of antituberculous drugs in a patient without active tuberculosis.

A 56-year old patient presented 3 months after initiation of an antituberculous regimen with Isoniacid (INH, 5 mg/kg daily), Ethambutol (20 mg/kg daily) and Rifampicin (675 mg daily) a mild sensory polyneuropathy and a bilateral retrobulbar neuritis which progressed to a severe optic atrophy. Multiple hyperintense foci were detected with NMR-imaging in the cerebral white matter suggestive of demyelination. INH and Ethambutol are known for their neurotoxic effects but suggestion was made that neurologic signs may not be due to drug neurotoxicity but could be induced by immunological processes initiated by the tubercle bacillus. In the reported patient the suspected tuberculosis of the urogenital tract was never proved histologically. Most likely his neurological symptoms were therefore cause by the administration of INH and Ethambutol. Patients with a low serum zinc level and a slow acetylation of INH are reported to be at special risk; both factors were present in our patient.

Antitubercular Agents↗
PubMed2003

[Severe course and contingent risk factors in optic neuropathy and myelopathy after tuberculostatics].

A male patient with tuberculous lymphadenopathy was treated with a four-fold therapy of ethambutol, isoniacide, rifampicin and pyracinamide. After 10 weeks the patient suffered from photophobia. Although ethambutol was discontinued vision decreased and visual field defects occurred as well as signs of myelopathy. Isoniacide was then discontinued and in the subsequent phase the vision was slowly restored over a period of 36 months. The combined toxicity of ethambutol and isoniacide seems to have been the main cause of the severe and protracted optic neuropathy.

Adult↗